Magnetic sensors are widely used in modern industrial and electronic products to sense the magnetic field intensity to measure physical parameters such as current, position and direction. In the prior art, there are many different types of sensors which are used for measuring the magnetic field and other parameters, such as magnetic sensors using Hall element, Anisotropic Magnetoresistance (AMR) element or Giant Magnetoresistance (GMR) element as sensing elements.
Although Hall magnetic sensors can work in high-intensity magnetic fields, they have disadvantages of low sensitivity, large power consumption, poor linearity and the like. Although AMR magnetic sensors have higher sensitivity than Hall magnetic sensors, the manufacturing process thereof is complex, the power consumption is high and thus they are not suitable for high-intensity magnetic fields. GMR magnetic sensors have higher sensitivity than Hall magnetic sensors, however, its linearity range is relatively small and thus they are not suitable for high-intensity magnetic fields, either.
TMR (Tunneling MagnetoResistive) magnetic sensors are novel magnetoresistive effect sensors which have been industrially applied in recent years, they use a tunneling magnetoresistive effect of magnetic multilayer film materials to sense the magnetic fields and have higher sensitivity, lower power consumption, better linearity and wider working range than Hall magnetic sensors, AMR magnetic sensors and GMR magnetic sensors. However, the existing TMR magnetic sensors are still not suitable for working in high-intensity magnetic fields, and the linearity range is not wide enough.